Decrease of spermatozoa with an unbalanced chromosome content after cell sorting in men carrying a structural chromosomal abnormality.

BACKGROUND: We showed that in men with a constitutional chromosomal abnormality, DNA fragmentation was significantly higher in chromosomally unbalanced spermatozoa than in spermatozoa with a normal or balanced chromosomal content. These results could be explained by a phenomenon already described in infertile men: abortive apoptosis. OBJECTIVES: To determine whether magnetic-activated cell separation could select spermatozoa with lower levels of DNA fragmentation and unbalanced chromosome content in men carrying a structural chromosomal abnormality. MATERIALS AND METHODS: The spermatozoa of ten males with a chromosomal rearrangement were separated into two populations using magnetic-activated cell separation (annexin V (-) and annexin V (+) fractions), in order to study meiotic segregation by fluorescence in situ hybridization, the percentage of spermatozoa with an externalization of phosphatidylserine by annexin V staining and DNA fragmentation by TdT-mediated dUTP nick-end labeling on the whole ejaculate and on selected spermatozoa in the same patient. RESULTS: For all patients, the percentage of spermatozoa with externalization of phosphatidylserine decreased in the annexin V (-) fraction and increased in the annexin V (+) fraction as compared to the frozen-thawed semen sample. The rates of DNA fragmentation were statistically much lower in the annexin V (-) fraction when compared to the rate before magnetic-activated cell separation for all but one patient. Conversely, we observed a statistically significantly higher rate of DNA fragmentation in the annexin V (+) fraction for six patients. After magnetic-activated cell separation, there was a significant increase of normal/balanced spermatozoa in the fraction of annexin V (-) for all patients. Conversely, we observed a significant decrease in the fraction of annexin V (+) for seven patients. DISCUSSION AND CONCLUSIONS: Magnetic-activated cell separation is a promising tool for increasing the selection of healthy spermatozoa, with a decrease in the number of spermatozoa with externalization of phosphatidylserine, DNA fragmentation, and chromosome unbalance, for use in assisted reproductive technologies such as intracytoplasmic sperm injection for males with a chromosomal structural abnormality.

[Contribution of high fidelity simulation to training in respiratory medicine]. / Apport de l'apprentissage par la simulation dans l'enseignement de la pneumologie.

INTRODUCTION: Simulation maintains patient safety by limiting the risk of errors. In the medical field, simulation is a method of learning that is developing more and more in the acute specialties but it is still not widespread in the field of respiratory medicine. OBJECTIVE: To evaluate the efficacy of high fidelity simulation as a teaching tool in respiratory medicine. METHODS AND POPULATION STUDIED: This was a prospective and descriptive study including students who had high fidelity simulation training sessions during their traineeship in respiratory medicine. Simulation learning took the form of four teaching sessions. The included students were assessed at the beginning and end of each session by a pre-test and post-test. Student satisfaction was assessed at the end of each session. RESULTS: Comparing the average student score before and after the simulation session showed an improvement in post-test scores. This improvement was statistically significant for all four scenarios. The majority of students, 60% (N=13), were satisfied with the progress of their internship in the Respiratory Department. CONCLUSION: High fidelity simulation is a teaching method that allows the acquisition and/or optimization of several skills. Nevertheless, this method remains undeveloped in respiratory medicine.